Well, I split the difference. I loaded up sixteen ounces of 15% Omega with a lot of extra castor, and ran the first tank "hot" (mainly wide open, at three turns out; IOW, she was spitting as much raw fuel as she was burning) with an 11x4 APC. The second tank had a bit of throttle work, but all in the upper power band.

Then I put the flight prop & spinner, 11x6 APC, on and ran the third tank with straight 15% Omega, going in to two turns on the big needle; again staying in the upper power band.

The fourth tank was at 1.5 turns out on the main needle. I had to lean the low end considerably, but by the end of the fourth tank the engine was holding 2200 rpm steadily at idle, smoothly transitioning to full throttle and holding 11,200 rpm without sagging; and still blowing good smoke. We'll leave it there for flying; no sense in wasting any more fuel on the bench.

In short, this OS .46 AX handled as well as any older FSR or SF I've dealt with, and settled down MUCH more quickly than some of them did. We'll see how it performs in the air, and how it holds up, but so far I've been rather impressed.

I was bit put off by some of the obvious shortcuts OS took (only four head bolts, a really cheap-looking {and loose-fitting} thrust washer/prop driver, plastic needle valve assembly, etc.) but the actual running was as good as you could ask for; IOW, absolutely no drama.

The various comments posted in this thread have been quite interesting, and I now have a greater appreciation for some of them. I'm about halfway convinced that one could run this thing just about any way he chose (except for too lean) and come out okay. Perhaps the "new" metallurgy, or whatever, isn't as el cheapo as some would think; and I believed.

The proof, of course, is in the flying and longevity. The jury is still out on that...